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Scientists just published a paper with the first-ever estimate of all the plastic garbage floating in the world's oceans.

The results were astronomical: More than 5 trillion pieces of plastic debris, weighting 269,000 tons. These bits of garbage are distributed throughout the world -- equally likely to be found in the tropical waters of the South Pacific as the glacial bays of Alaska.

But what's even more telling is what the scientists didn't find in their surveys. While researchers expected to discover a large amount of microplastics, that is, plastics which have been broken down by the sun and waves into pieces smaller than 5 millimeters, the number of microplastics were an order of magnitude smaller than expected.

This recent study confirms other researchers' observations that there is a large discrepancy between expected and observed microplastic weight and abundance in the world's oceans. So, less garbage than expected -- good news, right?

Wrong. These bits of plastic didn't magically disappear -- instead, they have been eaten by fish, turtles and other animals that mistake the particles for food. In addition, many of these tiny pieces have sunk below the surface of the ocean, and either float in the water column where surveys can't reach, or have settled to the bottom where they can be ingested by snails and other bottom feeders.

When animals consume plastic, they also consume all the toxins used to create plastic, like BPA, along with all the pollutants in the water that plastics absorb while they float in the ocean. Studies have shown that the concentration of toxic chemicals, such as PCB and DDT, can be up to a million times greater in plastic debris than found in seawater. These chemicals are inherently toxic, and can cause serious physiological damage in animals. And since big fish eat little fish, more organisms ingest plastic particles indirectly via their prey organisms, and concentrate the chemicals up the food chain.

Larger pieces of litter, like plastic bags, pose their own problems for seals, sea turtles, birds and other animals that ingest them.

Plastics are a huge problem for our oceans, and it is only predicted to get worse. Almost 300 million tons of plastic are produced every year, and only 5 percent of the world's plastic is currently recycled. Researchers forecast the volume of oceanic plastic debris will only increase due to rising production of throwaway plastic, and consumers' insatiable desire for cheap and convenient plastic goods.

That, of course, assumes we'll keep doing what we're doing. But it doesn't have to be that way.

You can start by refusing single-use plastic goods, petitioning your town to enact plastic-bag bans and recycling every piece of plastic you can.

We'll need action at a higher level too. The Center for Biological Diversity, where I work, has petitioned the EPA to do more to keep plastics off our beaches and out of our oceans. You can do your part by pressuring your political representatives to take this issue seriously with new and aggressive policies that get us back on the right track.

Now that we know just how much garbage we are dealing with, it's time to start finding solutions to clean up our oceans.